Abstract: A dosing pump is provided comprising a working membrane defining a working area, and a pump drive for creating an oscillating movement of the working membrane. The direction of the pump drive can be inverted and the displacement element can be moved back and forth. The inventive dosing pump also comprises a position sensor for detecting the position of the pump drive, an electronic control system for the same, and a pump head in which an inlet valve and an outlet valve are arranged. The pump drive comprises a positioning motor and can be displaced back and forth in an oscillating manner, with the part thereof connected to the displacement element, in any range of its entire working displacement, according to a pre-determinable course, for a reduced pump capacity in relation to the maximum pump capacity. At least the inlet valve is externally controlled and comprises a motor-driven valve drive.

Abstract: A diaphragm dosing pump (1) has a rotary driving motor (3) electrically connected to control electronics (4). The motor is controlled in such a way that at the beginning and end of each dosing operation the driven diaphragm preferably always takes the same starting position, in particular a bottom dead center position. In order to achieve a reliable sealing behavior of the inlet and outlet valves even during slow working strokes and when the pressure difference between suction and compression sides is small, the valves are designed with elastic valve disks mounted without stress between their valve seat and an opposite rib-like stop.

Abstract: In a diaphragm pump flap valves accommodated in a pump head are provided which have a valve disk in which are situated valve flaps (14) circumscribed by partial ring-shaped recesses. These are respectively flexibly connected with the remaining valve disk (15) by means of a web (17). The valve disk is clamped between pump head elements in an area circumscribing each respective valve. In order to avoid material displacements and deformations resulting from the clamping from acting upon the web and the valve flap (14), it is provided that an opening (19) of the valve disk (15) is situated in a connecting area between valve flap (14), web (17) and outer clamping (18), facing away from the valve flap (14). Material displacements originating from the clamping area (18) can thereby no longer influence the valve flap (14) and the web (17), since a transmission of these material deformations is interrupted in the area of the opening (19).